/Engine/Source/Runtime/GeometryCore/Public/VectorTypes.h
dot product of V1 with PerpCW(V2), ie V2 rotated 90 degrees clockwise
namespace UE { namespace Geometry { template<typename T> constexpr T UE::Geometry::DotPerp ( const [UE::Math::TVector2](API\Runtime\Core\Math\TVector2)< T > & V1, const [UE::Math::TVector2](API\Runtime\Core\Math\TVector2)< T > & V2 ) } }